Electronic device

ABSTRACT

According to an example, an electronic device includes a component, a supply line providing a supply voltage, a transistor with a control input, a linear first control loop, and a non-linear second control loop. The transistor outputs an output voltage to the component depending on a signal applied to the control input. The linear first control loop includes an ADC to convert an analog output voltage level into a digital measurement signal, a controller to generate a digital control signal for the transistor depending on the digital measurement signal, and a DAC to convert the digital control signal into a first analog control signal. The non-linear second control loop is configured to generate a second analog control signal depending on the analog output voltage level. The second analog control signal is superimposed with the first analog control signal and the combined control signals are fed to the control input of the transistor.

REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Application 10 2021 115021.3, filed on Jun. 10, 2021. The contents of the above-referencedPatent Applications are hereby incorporated by reference in theirentirety.

TECHNICAL FIELD

Examples relate to electronic devices in general.

BACKGROUND

Electronic devices can contain multiple different components that needto be supplied with possibly different voltages. In addition to therequirement for a specific supply voltage, other requirements may alsoexist depending on the component, for example noise isolation from apower supply. It is desirable to supply components of electronic deviceswith the required power in an efficient manner (e.g. with the fewestpossible additional components and/or minimum chip area consumption),while ensuring that the respective requirements are met.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures do not reflect the actual proportions, but are intended toillustrate the principles of the various examples. In the following textvarious examples are described with reference to the following figures.

FIG. 1 illustrates the power supply of a component to be supplied in anelectronic device, in accordance with various aspects described.

FIG. 2 shows an example of the control of a pass device using a hardwarecontrol loop, according to one embodiment.

FIG. 3 illustrates the use of the voltage regulator from FIG. 2 in aradar device, in accordance with various aspects described.

FIG. 4 shows a control of a pass device using a microcontroller, inaccordance with various aspects described.

FIG. 5 illustrates the control of a pass device to supply a component tobe supplied using a single control loop implemented by amicrocontroller, in accordance with various aspects described.

FIG. 6 illustrates the control of a pass device by means of twosuperimposed control loops implemented by a microcontroller, inaccordance with various aspects described.

FIG. 7 illustrates the use of the controller of FIG. 6 in a radardevice, in accordance with various aspects described.

FIG. 8 shows an example of a delta-sigma digital-to-analog converter andan example of a delta-sigma analog-to-digital converter, in accordancewith various aspects described.

FIG. 9 shows a qualitative curve of the load current, the outputvoltage, and the gain voltage output by the gain loop, in accordancewith various aspects described.

FIG. 10 shows an electronic device, in accordance with various aspectsdescribed.

DESCRIPTION

The following detailed description refers to the enclosed figures, whichshow details and examples. These examples are described in sufficientdetail to enable the person skilled in the art to embody the invention.Other embodiments are also possible, and the examples can be modified interms of their structural, logical and electrical aspects withoutdeviating from the subject matter of the invention. The differentexamples are not necessarily mutually exclusive, but differentembodiments can be combined to create new embodiments. For the purposesof this description, the terms “connected” and “coupled” are used todescribe both a direct and an indirect connection, as well as a director indirect coupling.

FIG. 1 illustrates an example of a power supply of a component 101 to besupplied with power in an electronic device 100.

The electronic device 100 includes a supply line 102. The supply line102 can be connected to an external power supply via a connector. Forexample, the electronic device 100 may be arranged in a vehicle and thesupply line 102 is connected to a battery of the vehicle. However, thesupply line 102 can also be connected to an internal battery of theelectronic device 100.

The supply line 102 is not directly connected to the component 101 to besupplied, but via a transfer component known as a pass device 103,typically a transistor (field-effect transistor or bipolar transistor).This can be the case, for example, because the component 101 to besupplied requires a different voltage than that delivered by the supplyline 102. For example, in a vehicle, the supply line 102 delivers avoltage of 12V and the component to be supplied may require, forexample, 3.3V. Another reason for the pas device 103 may be that thecomponent 101 to be supplied is sensitive to voltage fluctuations in thepower supply. In this case, the pass device 103 is used to regulate thevoltage applied to the component 101 to be as stable as possible, ifnecessary at a level that is below the voltage level of the supply line(e.g. 3.3V instead of 12V). A control component 104 is provided tocontrol the pass device 103.

FIG. 2 shows an exemplary control of a pass device using a hardwarecontrol loop.

In this example, the pass device 103 and the control component 104 areimplemented by a low-dropout voltage regulator (LDO) 200. In thisexample, the pass device 103 is a field-effect transistor 203, the gateof which is controlled by a differential amplifier 204. The supply line202 applies an input voltage to the field effect transistor 203 and theoutput voltage output by the transistor 203 is compared with a referenceby the differential amplifier 204. The differential amplifier 204controls the gate of the differential amplifier 204 according to theresult of the comparison. The output voltage is fed to the component201. In this example, the control component thus uses one (or possiblymore) hardware loops to provide a stable output voltage during possiblytime-variable conditions. The variable conditions include, for example,characteristics of the pass device 203, capacitance of the component tobe supplied, load current consumed by the component 201.

When the illustrated type of output voltage regulation is used, there istypically a fixed trade-off between settling time and response time. Thenoise characteristic of the voltage regulator 200 is primarilydetermined by analog parameters (device physics, power consumption,size, and so on) of the first input stage. The first stage refers to thecomponent 204, since in practice the differential amplifier is typicallybuilt from a plurality of amplifier stages and also comprises aplurality of analog loops.

FIG. 3 illustrates an exemplary use of the voltage regulator from FIG. 2in a radar device 300.

In this example, the component to be supplied is an MMIC 301 (MonolithicMicrowave Integrated Circuit). The MMIC 301 is supplied by a voltageregulator 303, which in turn is supplied by a supply line 302 (possiblyvia a pre-regulator), as described with reference to FIG. 2 .

The radar device 300 includes a microcontroller 304 (e.g. an MCU (microcontroller unit) for radar signal processing. The microcontroller 304processes radar data supplied by the MMIC 301 (e.g. by performing one ormore Fourier transformations (FFT) and/or a post-processing of digitalradar reception signals, e.g. for direction determination) and deliversradar signals, sent via the MMIC 301, to the MMIC 301. The radar signalprocessing is performed as specified by software running on themicrocontroller 304.

The microcontroller 304 (e.g. an AURIX from Infineon Technologies AG) issupplied with power by a separate power supply circuit 305, here a PMIC(Power Management IC), which is supplied from the power line 302.

In such an application, the voltage regulator 303 (which is external tothe MMIC 301) is used to achieve noise isolation from the supply line302 for the MMIC 301. The voltage regulator 303, however, increases thespace requirements and the costs of the radar device 300. Depending onthe application, the output of the voltage regulator 303 must also bemonitored to ensure safety conditions are met (e.g. when used in avehicle).

In order to avoid the requirement of an external voltage regulator 303,in accordance with various embodiments the microcontroller 304 is used,in addition to its use for radar signal processing, to control a passdevice, and in this manner to control a supply voltage for the MMIC 301.For example, a flexible software-based multi-loop control may beimplemented using the microcontroller 304, which can meet differentrequirements of various components and loads (external to themicrocontroller) to be supplied.

FIG. 4 shows an exemplary control of a pass device 403 by means of amicrocontroller 404.

The pass device 403 (which is external to the microcontroller 404) is afield-effect transistor, for example, the gate of which is fed with acontrol signal generated by the microcontroller 404. As in the previousexamples, an input voltage is fed to the field-effect transistor 403from a supply line 402.

The microcontroller 404 generates the control signal 405 depending on ameasurement signal 406, which indicates the output voltage currentlyoutput by the field-effect transistor 403. The microcontroller 404executes appropriate open-loop (or closed-loop) control software forthis purpose.

In this case, the control component 104 is thus implemented by softwareexecuted on the microcontroller 404 to provide a stable output voltageduring possibly time-variable conditions. The time-variable conditionsinclude characteristics of the pass device 403, capacitance of thecomponent 401 to be supplied, load current consumed by the component401.

FIG. 5 illustrates an exemplary control of a pass device 503 to supply acomponent 501 using a single control loop implemented by amicrocontroller 504.

As in FIG. 4 , the pass device 503 is a field-effect transistor (e.g. anNMOS depletion transistor), which is supplied by a supply line 502.

The microcontroller 504 receives an analog measurement signal via aninput pin (e.g. measurement pin) and has a (hardware) delta-sigmaanalog-to-digital converter (ADC) 505, which converts the analogmeasurement signal, which is an analog signal for measuring the outputvoltage of the pass device 503, into a digital measurement signal andfeeds the digital measurement signal to a software task 506 running on aprocessor of the microcontroller 504. The software task 506 implements aPI control system and generates a digital control signal from thedigital measurement signal. This is converted by a (hardware)sigma-delta digital-to-analog converter (DAC) 507 of the microcontroller504 into an analog control signal, which is filtered by an analoglow-pass filter (e.g. an RC filter) 508 and then fed to the gate of thefield-effect transistor 503.

The delta-sigma ADC/DAC-based control loop shown in FIG. 5 , inparticular the delta-sigma ADC, enables very precise control of theoutput voltage. The properties of the sigma-delta DAC and the low-passfilter define the noise characteristic of the controller. Thedelta-sigma ADC/DAC-based control loop enables noise shaping, whichallows noise signals to be shifted into non-interfering frequencyranges. For example, noise can be shifted into frequency ranges that donot interfere with the signal processing performed by the MMIC 301.

The loop bandwidth is primarily defined by the digital filters of thedelta-sigma ADC and is relatively low (order of magnitude of 10 kHz). Inorder to achieve a low response time of the closed-loop control and, forexample, to be able to react quickly to rapid load changes, a furthercontrol loop (also referred to as a gain loop) is added in accordancewith various embodiments, as explained in the following with referenceto FIG. 6 .

FIG. 6 illustrates an exemplary control of a pass device 603 by means oftwo superimposed control loops implemented by a microcontroller 604.

Analogously to FIG. 5 , a first delta-sigma ADC/DAC-based control loopis implemented using a delta-sigma ADC 605, a first software task 606implemented in the controller 604, a delta-sigma DAC 607, and a low-passfilter 608. The analog control signal for the gate of the transistor603, output by this first control loop, is superimposed with a secondanalog control signal, which is generated by a second control loop.

The second control loop is formed as follows: a second analog-to-digitalconverter 609 receives an analog measurement of the output voltage andfrom it generates a digital measurement signal. The secondanalog-to-digital converter 609 is, for example, a SAR (SuccessiveApproximation Register) ADC or a simple fast comparator that comparesthe analog output voltage with a threshold value and outputs 1 or 0depending on the result of the comparison. The output of the secondanalog-to-digital converter 609 is fed to a second software task 610that the microcontroller executes. The second software task 610 feeds asecond analog control signal to the gate of the transistor 603 via anoutput interface 611 (e.g. a GPIO (General Purpose Input/Output)) of themicrocontroller 604 and via a resistor 612, depending on the output ofthe second analog-to-digital converter 609, so that the second controlsignal is superimposed on the first control signal (e.g., the secondcontrol signal is added to the first control signal). The outputinterface 611 outputs a gain voltage via a gain pin to the resistor 612.

According to one example, the second analog control signal is a DCsignal with two possible levels, either the second software task 610extracts charge from the gate of the transistor 603 (e.g. if the outputvoltage is above a threshold value), feeds charge to the gate of thetransistor 603 (e.g. if the output voltage is below a threshold value)or neither of these (e.g., by switching the respective output pin of themicrocontroller 604 to high impedance). For example, two thresholdvalues may be provided and the second software task 610 controls theoutput interface 611 to output a positive level DC current if the outputvoltage is below the lower of the two threshold values, controls theoutput interface 611 to output a negative level DC current if the outputvoltage is above the higher of the two threshold values, and switchesthe output pin of the output interface 611, which is connected to thegate of transistor 603 (via the resistor 612), to high impedance if theoutput voltage lies between the two threshold values (i.e. within atolerance range defined by the threshold values).

The comparison can be performed by the second ADC converter 609 or bythe second software task 610 (in the event that the ADC converter 609generates a conversion of the analog to a digital value of the outputvoltage).

Due to the generation of the second analog control signal on the basisof a (simple) comparison, the second control loop is non-linear. Thesecond control loop enables a rapid response to changes in the outputvoltage (asynchronously with the first control loop). In other words,the second control loop has a higher control bandwidth than the firstloop. The second control loop is also referred to herein as a gaincontrol loop.

FIG. 7 illustrates an exemplary use of the controller of FIG. 6 in aradar device 700.

As in the example of FIG. 3 , the component to be supplied is an MMIC701. The MMIC 701 is supplied with power via a transistor 703, which asdescribed with reference to FIG. 7 is controlled by a microcontroller704. The transistor 703 receives an input current from a supply line702. In this example, a pre-regulator 707 is provided (e.g. a DCstep-down converter for converting from 12V to approximately 4.5V).

The microcontroller 704 (e.g. an AURIX from Infineon Technologies AG) issupplied with power by a separate power supply circuit 705, here a PMIC(Power Management IC), which is supplied from the power line 702. Thedelta-sigma DAC 607 is implemented here by a HSDPM (High Speed PulseDensity Modulation Module 706).

The microcontroller 704 can provide fail-safe mechanisms in case theoutput voltage drops too low.

Returning to FIG. 6 , a CPU of the microcontroller 604, which executesthe software tasks 606, 610, can be connected to the GPIO 611, the DAC607, the ADC 605 and the second ADC via register interfaces. Thelow-pass filter 608 can comprise one RC filter or a plurality of RCfilters in series.

One or both of the software tasks 606, 610 can also be executed in othermodules of the microcontroller 604 instead of in the microcontroller CPUin alternative examples. For example, the software task 610 can beexecuted in the GPIO 611. In particular, the two software tasks 606, 610can be executed on different data processing components.

The output interface 611 can comprise a level shifter and a buffer (e.g.in the form of an inverter). This can also be provided at the output ofthe DAC 607. A digital low-pass filter may be provided between thedelta-sigma ADC 605 and the CPU (including, for example a CIC (CascadedIntegrator Comb) filter followed by a FIR (Finite Input Response)filter).

FIG. 8 shows an example of a delta-sigma DAC 801 and an example of adelta-sigma ADC 802, each of which is second order with fastfeed-forward. The delta-sigma DAC 801 has a digital down converter (DDC)803 in the feedback section.

FIG. 9 shows an exemplary qualitative curve of the load current (firstgraph 901), the output voltage (second graph 902) and the gain voltageoutput from the gain loop at the gain pin (third graph 903).

In this example, the load current changes (e.g. by approx. 800 mA) andthen fluctuates rapidly in a region 904. The change is compensated bythe linear first control loop (i.e. the delta-sigma ADC/DAC-basedcontrol loop). The fluctuations in the region 904 are compensated bycorresponding fast pulses of the gain voltage.

In summary, according to various examples an electronic device as shownin FIG. 10 is provided.

FIG. 10 shows an electronic device 1000 according to one example.

The electronic device 1000 includes a component 1001 to be supplied, asupply line 1002 that provides a supply voltage, and a transistor 1003with a control input 1004 to which the supply voltage from the supplyline is fed and which is configured to output an output voltagedepending on its control input 1004 to supply the component 1001.

The electronic device 1000 also includes a linear first control loop,which includes a delta-sigma analog-to-digital converter 1005 configuredto convert the analog output voltage level into a digital measurementsignal, a controller 1006 configured to generate a digital controlsignal for the transistor 1003 depending on the digital measurementsignal, and a delta-sigma digital-to-analog converter 1007 configured toconvert the digital control signal into a first analog control signaland feed it to the control input 1004 of the transistor 1003.

The electronic device 1000 also includes a non-linear second controlloop 1008, which is configured to generate a second analog controlsignal depending on the analog output voltage level and feed it to thecontrol input 1004 of the transistor, superimposed with the first analogcontrol signal.

In other words, two control loops are provided, the first control loopbeing a linear, delta-sigma ADC/DAC-based control loop that ensures highaccuracy, while the second control loop is a non-linear control loop(with higher control bandwidth) that ensures a low response time.

The use of a plurality of control loops also enables a flexibletrade-off between settling time and response time, as differentperipheral components of a microcontroller can be used for the controlloops (e.g. HSPDM for the first control loop and GPIO for the secondcontrol loop, as well as different ADCs). Furthermore, due to the use ofdelta-sigma converters the noise characteristic does not dependprimarily on analog parameters.

In the following text, various examples are specified.

Example 1 is an electronic device, including a component to be supplied,a supply line providing a supply voltage; a transistor to which thesupply voltage is fed from the supply line, the transistor including acontrol input and configured to output an output voltage depending on asignal applied to the control input to supply the component; a linearfirst control loop, and a non-linear control loop. The linear firstcontrol loop includes a delta-sigma analog-to-digital converterconfigured to convert an analog output voltage level into a digitalmeasurement signal, a controller configured to generate a digitalcontrol signal for the transistor depending on the digital measurementsignal, and a delta-sigma digital-to-analog converter configured toconvert the digital control signal into a first analog control signaland feed it to the control input of the transistor. The non-linearsecond control loop is configured to generate a second analog controlsignal depending on the analog output voltage level and feed it to thecontrol input of the transistor, wherein the second analog controlsignal is superimposed with the first analog control signal.

Example 2 includes the subject matter of example 1, including oromitting optional elements, wherein the controller is configured togenerate the digital control signal for the transistor from a controlerror between an output voltage level indicated by the digitalmeasurement signal and a reference variable for the output voltage.

Example 3 includes the subject matter of example 1, including oromitting optional elements, wherein the controller is a PI controller.

Example 4 includes the subject matter of example 1, including oromitting optional elements, wherein the delta-sigma digital-to-analogconverter is configured to feed the first analog control signal to thecontrol input of the transistor via a low-pass filter.

Example 5 includes the subject matter of example 1, including oromitting optional elements, wherein the non-linear second control loopincludes a comparator configured to compare the analog output voltagelevel with a threshold value, and generate the second analog controlsignal dependent on a result of the comparison.

Example 6 includes the subject matter of example 1, including oromitting optional elements, wherein the non-linear second control loopincludes an analog-to-digital converter configured to convert the analogoutput voltage level into a digital level of the output voltage, comparethe digital level of the output voltage with a threshold value, andgenerate the second analog control signal depending on a result of thecomparison.

Example 7 includes the subject matter of example 1, including oromitting optional elements, wherein the second analog control signal hasone of two levels.

Example 8 includes the subject matter of example 1, including oromitting optional elements, wherein the transistor is a field-effecttransistor and wherein the non-linear second control loop is configuredto generate the second analog control signal depending on the analogoutput voltage level, wherein charge is extracted from a gate of thefield-effect transistor or charge is fed to the gate of the field-effecttransistor based on the second analog control signal.

Example 9 includes the subject matter of example 1, including oromitting optional elements, wherein the non-linear second control loopis configured not to feed the second analog control signal to thecontrol input of the transistor if the analog output voltage level lieswithin a pre-defined tolerance range.

Example 10 includes the subject matter of example 1, including oromitting optional elements, including a microcontroller with aprocessor, wherein the controller is implemented by a software taskrunning on the processor.

Example 11 includes the subject matter of example 10, including oromitting optional elements, wherein the microcontroller includes thedelta-sigma analog-to-digital converter and the delta-sigmadigital-to-analog converter.

Example 12 includes the subject matter of example 10, including oromitting optional elements, wherein the second non-linear control loopis implemented by a digital-to-analog converter or a comparator of themicrocontroller, a further software task running on the processor, andan output interface of the microcontroller.

Example 13 includes the subject matter of example 1, including oromitting optional elements, wherein the electronic device is a radardevice and the component to be supplied is a monolithic microwaveintegrated circuit.

Example 14 is a method for controlling an output voltage supplied to acomponent of an electronic device, including generating a first controlsignal based on a control error between an output voltage level of atransistor and a reference variable for the output voltage level;generating a second control signal based on a comparison of the outputvoltage level of the transistor and at least one threshold voltage; andfeeding the first control signal and the second control signal,superimposed with respect to one another, to a gate of the transistor tocontrol the transistor to output the output voltage.

Example 15 includes the subject matter of example 14, including oromitting optional elements, including converting the output voltagelevel into a digital measurement signal, generating a digital controlsignal for the transistor depending on the digital measurement signal,and converting the digital control signal into the first control signal.

Example 16 includes the subject matter of example 14, including oromitting optional elements, including filtering the first control signalwith a low-pass filter and feeding the filtered first control signal tothe gate of the transistor.

Example 17 includes the subject matter of example 14, including oromitting optional elements, including generating the second controlsignal to exhibit either a first value that causes charge to beextracted from the gate of the transistor when the output voltage levelexceeds a first threshold or a second value that causes charge to be fedto the gate of the transistor when the output voltage level is below asecond threshold.

Example 18 includes the subject matter of example 17, including oromitting optional elements, including generating the second controlsignal to exhibit a third value that causes the gate of the transistorto be tied to a high impedance input when the output voltage level liesbetween the first threshold and the second threshold.

Example 19 is a power supply system for a component of an electronicdevice, including a transistor to which supply voltage is fed from asupply line, the transistor including a control input and configured tooutput an output voltage depending on a signal applied to the controlinput, wherein the output voltage is provided to the component. Thepower supply system includes a linear first control loop, including adelta-sigma analog-to-digital converter configured to convert an analogoutput voltage level into a digital measurement signal, a controllerconfigured to generate a digital control signal for the transistordepending on the digital measurement signal, and a delta-sigmadigital-to-analog converter configured to convert the digital controlsignal into a first analog control signal and feed it to the controlinput of the transistor. The power supply system includes a non-linearsecond control loop, configured to generate a second analog controlsignal depending on the analog output voltage level and feed it to thecontrol input of the transistor, wherein the second analog controlsignal is superimposed with the first analog control signal.

Example 20 includes the subject matter of example 19, including oromitting optional elements, wherein the controller is configured togenerate the digital control signal for the transistor from a controlerror between an output voltage level indicated by the digitalmeasurement signal and a reference variable for the output voltage.

Example 21 includes the subject matter of example 19, including oromitting optional elements, including a low-pass filter and wherein thedelta-sigma digital-to-analog converter is configured to feed the firstanalog control signal to the control input of the transistor via thelow-pass filter.

Example 22 includes the subject matter of example 19, including oromitting optional elements, wherein the non-linear second control loopincludes an analog-to-digital converter configured to convert the analogoutput voltage level into a digital level of the output voltage, comparethe digital level of the output voltage with at least one thresholdvalue, and generate the second analog control signal depending on aresult of the comparison, wherein the second analog control signal hasone of two levels.

Example 23 includes the subject matter of example 19, including oromitting optional elements, wherein the transistor is a field-effecttransistor and wherein the non-linear second control loop is configuredto generate the second analog control signal depending on the analogoutput voltage level, wherein the second analog control signal causescharge to be extracted from a gate of the field-effect transistor whenthe analog output voltage level is above a first threshold and causescharge to be fed to the gate of the field-effect transistor when theanalog output voltage level is below a second threshold.

Example 24 includes the subject matter of example 19, including oromitting optional elements, wherein the non-linear second control loopis configured not to feed the second analog control signal to thecontrol input of the transistor if the analog output voltage level lieswithin a pre-defined tolerance range.

Example 25 is an electronic device as described above with reference toFIG. 10 .

Example 26 is the electronic device according to example 25, wherein thecontroller is configured to generate the digital control signal for thetransistor from the control error between the output voltage levelindicated by the digital measurement signal and a reference variable forthe output voltage.

Example 27 is the electronic device according to example 25 or 26,wherein the controller is a PI controller.

Example 28 is the electronic device according to one of the examples 25to 27, wherein the delta-sigma digital-to-analog converter is configuredto feed the first analog control signal to the control input of thetransistor via a low-pass filter.

Example 29 is the electronic device according to one of the examples 25to 28, wherein the non-linear control loop comprises a comparator whichis configured to compare the analog level of the output voltage with athreshold value and to generate the second analog control signaldepending on a result of the comparison.

Example 30 is the electronic device according to one of the examples 25to 29, wherein the non-linear control loop comprises an analog-digitalconverter, which is configured to convert the analog level of the outputvoltage into a digital level of the output voltage, to compare thedigital level of the output voltage with a threshold value and togenerate the second analog control signal depending on a result of thecomparison.

Example 31 is the electronic device according to one of the examples 25to 30, wherein the second analog control signal has one of two levels.

Example 32 is the electronic device according to one of the examples 25to 31, wherein the transistor is a field-effect transistor and whereinthe non-linear second control loop is configured to generate the analogcontrol signal depending on the analog level of the output voltage insuch a way that it extracts charge from the gate of the field-effecttransistor or that it feeds charge to the gate of the field-effecttransistor.

Example 33 is the electronic device according to one of the examples 25to 31, wherein the non-linear second control loop is configured not tofeed the second analog control signal to the control input of thetransistor when the analog level of the output voltage lies within apredefined tolerance range.

Example 34 is the electronic device according to one of the examples 25to 34, comprising a microcontroller with a processor, wherein thecontroller is implemented by a software task running on the processor.

Example 35 is the electronic device according to example 34, wherein themicrocontroller contains the delta-sigma analog-to-digital converter andthe delta-sigma digital-to-analog converter.

Example 36 is the electronic device according to example 34 or 35,wherein the second non-linear control loop is implemented by adigital-to-analog converter or a comparator of the microprocessor, afurther software task running on the processor, and an output interfaceof the microcontroller.

Example 37 is the electronic device according to one of the examples 25to 36, wherein the electronic device is a radar device and the componentto be supplied is a monolithic microwave integrated circuit.

Although the invention has mainly been shown and described by referenceto specific embodiments, it should be understood by those familiar withthe technical field that numerous changes can be made with regard to itsdesign and details without departing from the nature and scope of theinvention, as defined by the following claims. The scope of theinvention is therefore defined by the attached claims and it is intendedthat any changes that fall within the literal meaning or equivalentscope of the claims are included.

LIST OF REFERENCE SIGNS

-   -   100 electronic device    -   101 device to be supplied    -   102 supply line    -   103 pass device    -   104 control component    -   200 low-dropout voltage regulator    -   201 component to be supplied    -   202 supply line    -   203 pass device    -   204 differential amplifier    -   300 radar device    -   301 MMIC    -   302 supply line    -   303 voltage regulator    -   304 microcontroller    -   305 power supply circuit    -   401 component to be supplied    -   402 supply line    -   403 pass device    -   404 microcontroller    -   405 control signal    -   406 detected signal    -   501 component to be supplied    -   502 supply line    -   503 field-effect transistor    -   504 microcontroller    -   505 delta-sigma analog-to-digital converter    -   506 software task    -   507 sigma-delta digital-to-analog converter    -   508 low-pass filter    -   603 transistor    -   604 microcontroller    -   605 ADC    -   606 controller    -   607 DAC    -   608 low-pass filter    -   609 analog-to-digital converter    -   610 software task    -   611 GPIO    -   612 resistor    -   700 radar device    -   701 MMIC    -   702 supply line    -   703 transistor    -   704 microcontroller    -   705 power supply circuit    -   706 HSDPM    -   707 pre-regulator    -   801 DAC    -   802 ADC    -   803 step-down converter    -   901 load current graph    -   902 output voltage graph    -   903 gain-voltage graph    -   904 fluctuation region    -   1000 electronic device    -   1001 component to be supplied    -   1002 supply line    -   1003 transistor    -   1004 transistor control input    -   1005 delta-sigma analog-digital converter    -   1006 controller    -   1007 delta-sigma digital-to-analog converter    -   1008 non-linear control loop

What is claimed is:
 1. An electronic device, comprising: a component tobe supplied; a supply line providing a supply voltage; a transistor towhich the supply voltage is fed from the supply line, the transistorcomprising a control input and configured to output an output voltagedepending on a signal applied to the control input to supply thecomponent; a linear first control loop, comprising a delta-sigmaanalog-to-digital converter configured to convert an analog outputvoltage level into a digital measurement signal, a controller configuredto generate a digital control signal for the transistor depending on thedigital measurement signal, and a delta-sigma digital-to-analogconverter configured to convert the digital control signal into a firstanalog control signal and feed it to the control input of thetransistor; a non-linear second control loop, configured to generate asecond analog control signal depending on the analog output voltagelevel and feed it to the control input of the transistor, wherein thesecond analog control signal is superimposed with the first analogcontrol signal; and a microcontroller with a processor, wherein thecontroller is implemented by a software task running on the processor,wherein the non-linear second control loop is implemented by adigital-to-analog converter or a comparator of the microcontroller, afurther software task running on the processor, and an output interfaceof the microcontroller.
 2. The electronic device of claim 1, wherein thecontroller is configured to generate the digital control signal for thetransistor from a control error between an output voltage levelindicated by the digital measurement signal and a reference variable forthe output voltage.
 3. The electronic device of claim 1, wherein thecontroller is a PI controller.
 4. The electronic device of claim 1,wherein the delta-sigma digital-to-analog converter is configured tofeed the first analog control signal to the control input of thetransistor via a low-pass filter.
 5. The electronic device of claim 1,wherein the non-linear second control loop comprises a comparatorconfigured to compare the analog output voltage level with a thresholdvalue, and generate the second analog control signal dependent on aresult of the comparison.
 6. The electronic device of claim 1, whereinthe non-linear second control loop comprises an analog-to-digitalconverter configured to convert the analog output voltage level into adigital level of the output voltage, compare the digital level of theoutput voltage with a threshold value, and generate the second analogcontrol signal depending on a result of the comparison.
 7. Theelectronic device of claim 1, wherein the second analog control signalhas one of two levels.
 8. The electronic device of claim 1, wherein thetransistor is a field-effect transistor and wherein the non-linearsecond control loop is configured to generate the second analog controlsignal depending on the analog output voltage level, wherein charge isextracted from a gate of the field-effect transistor or charge is fed tothe gate of the field-effect transistor based on the second analogcontrol signal.
 9. The electronic device of claim 1, wherein thenon-linear second control loop is configured not to feed the secondanalog control signal to the control input of the transistor if theanalog output voltage level lies within a pre-defined tolerance range.10. The electronic device of claim 1, wherein the microcontrollercomprises the delta-sigma analog-to-digital converter and thedelta-sigma digital-to-analog converter.
 11. The electronic device ofclaim 1, wherein the electronic device is a radar device and thecomponent to be supplied is a monolithic microwave integrated circuit.12. A method for controlling an output voltage supplied to a componentof an electronic device, comprising: generating a first control signalbased on a control error between an output voltage level of a transistorand a reference variable for the output voltage level; generating asecond control signal based on a comparison of the output voltage levelof the transistor and at least one threshold voltage to exhibit either afirst value that causes charge to be extracted from a gate of thetransistor when the output voltage level exceeds a first threshold or asecond value that causes charge to be fed to the gate of the transistorwhen the output voltage level is below a second threshold; and feedingthe first control signal and the second control signal, superimposedwith respect to one another, to a gate of the transistor to control thetransistor to output the output voltage.
 13. The method of claim 12,comprising: converting the output voltage level into a digitalmeasurement signal, generating a digital control signal for thetransistor depending on the digital measurement signal, and convertingthe digital control signal into the first control signal.
 14. The methodof claim 12, comprising filtering the first control signal with alow-pass filter and feeding the filtered first control signal to thegate of the transistor.
 15. The method of claim 12, comprisinggenerating the second control signal to exhibit a third value thatcauses the gate of the transistor to be tied to a high impedance inputwhen the output voltage level lies between the first threshold and thesecond threshold.
 16. A power supply system for a component of anelectronic device, comprising: a transistor to which supply voltage isfed from a supply line, the transistor comprising a control input andconfigured to output an output voltage depending on a signal applied tothe control input, wherein the output voltage is provided to thecomponent; a linear first control loop, comprising a delta-sigmaanalog-to-digital converter configured to convert an analog outputvoltage level into a digital measurement signal, a controller configuredto generate a digital control signal for the transistor depending on thedigital measurement signal, and a delta-sigma digital-to-analogconverter configured to convert the digital control signal into a firstanalog control signal and feed it to the control input of thetransistor; and a non-linear second control loop, configured to generatea second analog control signal depending on the analog output voltagelevel and feed it to the control input of the transistor, wherein thesecond analog control signal is superimposed with the first analogcontrol signal, wherein the transistor is a field-effect transistor andwherein the non-linear second control loop is configured to generate thesecond analog control signal depending on the analog output voltagelevel, wherein the second analog control signal causes charge to beextracted from a gate of the field-effect transistor when the analogoutput voltage level is above a first threshold and causes charge to befed to the gate of the field-effect transistor when the analog outputvoltage level is below a second threshold.
 17. The power supply systemof claim 16, wherein the controller is configured to generate thedigital control signal for the transistor from a control error betweenan output voltage level indicated by the digital measurement signal anda reference variable for the output voltage.
 18. The power supply systemof claim 16, comprising a low-pass filter and wherein the delta-sigmadigital-to-analog converter is configured to feed the first analogcontrol signal to the control input of the transistor via the low-passfilter.
 19. The power supply system of claim 16, wherein the non-linearsecond control loop comprises an analog-to-digital converter configuredto convert the analog output voltage level into a digital level of theoutput voltage, compare the digital level of the output voltage with atleast one threshold value, and generate the second analog control signaldepending on a result of the comparison, wherein the second analogcontrol signal has one of two levels.
 20. The power supply system ofclaim 16, wherein the non-linear second control loop is configured notto feed the second analog control signal to the control input of thetransistor if the analog output voltage level lies within a pre-definedtolerance range.